| abstract |
A process for preparing olefinic living polymers having anmolecular weight distribution (Mw/Mn) of 1 to 1.3, comprisingnpolymerizing an olefinic monomer having 2 to 20 carbon atoms at lowntemperatures in the presence of a catalyst comprising (A) a hafnium ornzirconium-containing compound having one or two cyclopentadienylnbackbones, (B) a triphenyl boron compound or a tetraphenyl boratencompound and optionally (C) a specific mono-, di- or trialkylaluminumncompound. When the catalyst comprising the zirconium-containingncompound is prepared by further using a titanium-containingncompound (D), the polymerization temperature can be raised. |